# Loft insulation across Cambridgeshire > Loft insulation across Cambridgeshire, laid to the 270mm assessors recommend. Free survey, a written price, and we will tell you if yours does not need doing. Source: https://completeloftservices.co.uk/loft-insulation/ Generated: 2026-09-21 --- - [Home](/) - Services - Loft insulation # Loft insulation across Cambridgeshire Laid to 270mm, cross laid so there are no gaps at the joists, and worked around the cables and downlights rather than over them. Free survey, a written price, and if your loft does not need doing we will say so. It is usually worth doing [alongside boarding](/loft-boarding-and-insulation/), because the loft is open either way. [Book a free survey](#enquire) [Doing it with boarding](/loft-boarding-and-insulation/) ## 270mm, and why that is the number It is the depth an energy assessor writes on a certificate when a loft is short, and it is what we lay to unless there is a reason not to. You can look up what your own certificate records. Most Cambridgeshire lofts are somewhere between bare joists and about half of that: the commonest depth recorded on a certificate here is 100mm, on 28,002 homes. Usually the house was insulated once, years ago, and never topped up. The full picture is further down this page. ### What the register records most 100mm One layer between the joists, flattened in places, missing where somebody has been up for the Christmas boxes, and stopping short at the eaves. ### What we leave 270mm A layer between the joists and a second layer across them, so the timber is covered too and there is no cold line where the joists run. Cross laying matters more than people expect. A joist is a cold bridge: insulate only between them and you leave a grid of cold stripes across the ceiling. The second layer is what stops that, and it is also why a loft that is going to be [boarded](/loft-boarding/) needs the floor raised clear of it. There is a fuller answer in can you board over loft insulation, and if you are weighing 270mm against going deeper, that is here. ## What Cambridgeshire lofts actually have in them 53,949 houses and bungalows in our six councils are recorded with less than 150mm of loft insulation. That is 30.3% of every home where a depth was measured. - Nothing at all10,769 - 50mm4,653 - 75mm7,872 - 100mm28,002 - 150mm21,587 - 200mm30,027 - 250mm30,276 - 270mm or more36,242 We read 143 million rows of the public certificate register and kept the 248,651 houses and bungalows in Cambridge, South Cambridgeshire, East Cambridgeshire, Huntingdonshire, Fenland and Peterborough. 10,769 of them have no loft insulation recorded at all. It is the state of each home at the date it was assessed, so some will have been done since. The picture is much the same in Cambridge, Huntingdon, Ely, St Neots and Peterborough, and reading your own EPC takes a minute. Source: [Energy Performance of Buildings Register](https://get-energy-performance-data.communities.gov.uk/), bulk domestic download, analysed September 2026. Depths are as recorded by the assessor. ## What we do up there - 1 ### Measure what is already there Depth in several places, not one. We look at the eaves, the hatch, whether the old material is dry, and whether anything has been walked flat. How much you actually need follows from that. - 2 ### Clear and make safe Anything stored up there comes out of the way first, and we can clear the whole loft if that is easier. Cables get lifted clear rather than buried, and downlights are dealt with properly instead of being covered. - 3 ### Lay between, then across A layer between the joists, then a second layer at right angles over the top, taken to the eaves without blocking the airflow that keeps the roof dry. - 4 ### Finish the edges The loft hatch is the hole in the middle of the work, so it gets insulated and draught sealed. If yours is small or awkward, enlarging it or fitting a [ladder](/loft-ladders/) is quoted separately. Then we bag the waste, take it with us, and show you what has changed. ## Top up, or take it out Most lofts only need adding to. Some need the old material out first, and that is a bigger job, so it is decided at the survey rather than on the day. Which one is yours? - ### Dry, clean, just shallow Leave it where it is and lay over the top. Cheapest outcome, least waste, and the usual answer. Top up - ### Damp, or smells of it Wet insulation does nothing and points at a roof problem, and sometimes at condensation rather than a leak. It comes out, and the cause gets looked at before anything new goes down. Remove - ### Vermin have been in it It comes out and goes in bags. This is not a judgement on the house, it is common in older lofts with open eaves. Remove - ### Loose fill, blown or flat Old granular fill and flattened quilt can both stay if they are dry, as long as the new depth is measured from the top of what is there. Depends ## What is not included, said out loud Insulation quotes grow in the same few places. Each of these is priced on its own line, so you decide before we start rather than halfway through. - ### Clearing the loft If it is full, it has to be emptied before anything can be laid. We can do that and take away what you no longer want. - ### Taking out old insulation Bagging and disposing of wet, dirty or vermin damaged material is a job in itself, and it is not in the price of laying new. - ### Downlight covers Fire rated covers over recessed lights, where they are needed, are a separate item and sometimes an electrician's call. - ### [Boarding](/loft-boarding/) If you want a floor as well, it goes on raised legs above the new depth. Quoted together, priced separately. - ### Roof repairs If the felt or the tiles are the real problem, insulation will not fix it. We get the roof sorted first, with a roofer we bring in, then do the loft. - ### [Spray foam](/spray-foam-removal/) Foam on the underside of the roof changes everything, including mortgages. It needs assessing independently before any insulation work. One thing you will not find here. A "save £300 a year" headline. Those numbers are mostly unsourced and they depend on your house, your heating and what is up there now. We would rather measure your loft and show you what the work costs than guess at your bill. ## What we would do with your loft Not every loft needs the same thing, and the survey is free precisely so you find out before you spend anything. Either way you get a straight answer and a price for the work that is actually worth doing. ### Insulation is the job Under 150mm, or nothing at all. Gaps at the eaves. One thin layer with the joists showing through. Old material that is damp or has been lived in. A loft you are about to board anyway. ### Something else first, then this Already at 270mm and dry, so [boarding](/loft-boarding/) is what gets you something. [Spray foam](/spray-foam-removal/) on the roof, which we take off first. A leak, which we get fixed before insulation goes anywhere near it. Or a [room in the roof](/loft-conversion/), which is a conversion and we can handle that too. ## Loft insulation questions we get asked **How deep should loft insulation be?** 270mm is the figure energy assessors write on certificates when a loft falls short, and it is what we lay to. It is usually a layer between the joists and a second layer across them, because the joists themselves need covering. **Can I get it done on a grant?** Possibly, but not through us. Grant schemes are means tested or tied to your energy rating and have their own approved installers, so if you qualify you are better off going straight to the scheme. We are a private job, priced and paid for directly, and we will say so plainly rather than take you through a form that goes nowhere. **Can you insulate and board at the same time?** Yes, and it is the sensible order. The insulation goes to full depth and the floor goes on legs above it, so nothing is crushed. It is one visit and one lot of mess instead of two, which is [the combined job](/loft-boarding-and-insulation/). **Will more insulation make the loft damp?** Not if the airflow at the eaves is kept clear, which is part of the job. A warmer house means a colder loft, so ventilation matters more after insulating, not less. If we find the eaves already blocked we will tell you. **What happens to the pipes and the water tank?** Insulation goes over the pipes, never under the tank. A tank sitting on a well insulated ceiling gets colder, so the tank and its pipework are lagged as part of the work. **Do I have to move everything out of the loft?** It has to be clear of the area being insulated, but we can do that for you and take away anything you have finished with. It is priced separately so you can see exactly what it adds. **How long does it take?** A straightforward loft is a few hours, and most are done inside a day including clearing up. Taking out old material, or a loft you cannot stand up in, adds time and we will say so at the survey. **What about the downlights in the ceiling?** They cannot simply be covered. Recessed lights need clearance or a fire rated cover, so we work around them and tell you if an electrician needs to be involved before we finish. ## The two jobs people usually ask about together Insulation is the half that saves heat. Boarding is the half that gets the loft back. Most people want both, and doing them in one visit is cheaper than doing them a year apart. [Insulation and boarding together Full depth underneath, a floor on legs above it, one visit.](/loft-boarding-and-insulation/) [Loft boarding on its own If the insulation is already at depth and dry, you only need the floor.](/loft-boarding/) ## Book a free survey this week It takes about twenty minutes and you get a written price with nothing hidden in it. If the job is not worth doing, we will tell you that too. [01223 000 000](tel:01223000000)